ugkfeaturedefn.h

linux下一款GIS程序源码

// ugkfeaturedefn.h: interface for the UGKFeatureDefn class.
//
/************************************************************************/
/*                            UGKFeatureDefn                            */
/************************************************************************/
/**                    一种具体的feature类的定义
**            UGKFeatureDefn定义了对于某一类几何类型的Feature，定义了字段数     
** 
**               而UGKFeature类则是根据某一个UGKFeatureDefn而定义的
 * Definition of a feature class or feature layer.
 *
 * This object contains schema information for a set of UGKFeatures.  In
 * table based systems, an UGKFeatureDefn is essentially a layer.  
 *
 * This object also can contain some other information such as a name, the
 * base geometry type and potentially other metadata.
 *
 * It is reasonable for different translators to derive classes from
 * UGKFeatureDefn with additional translator specific information. 
 */


#ifndef  UGKFeatureDefn_H
#define  UGKFeatureDefn_H


#include "ugkfielddefn.h"
#include "ugkglobal.h"

class UGKFeatureDefn  
{
private:
	int         nRefCount; // 引用个数，就是以这个FeatureDefn定义的Feature的个数
	int         nFieldCount;       //字段数


	UGKFieldDefn **papoFieldDefn;  //指向字段定义 ##02
	UGKwkbGeometryType eGeomType;  //这个Feature是什么几何类型(点、线……)

	char        *pszFeatureClassName;

public:
	UGKFeatureDefn( const char * pszName = NULL );
	virtual ~UGKFeatureDefn();

	const char  *GetName() { return pszFeatureClassName; }
	int         GetFieldCount() { return nFieldCount; }
	UGKFieldDefn *GetFieldDefn( int i );
    int         GetFieldIndex( const char * );

	void        AddFieldDefn( UGKFieldDefn * );
	UGKwkbGeometryType GetGeomType() { return eGeomType; }
	void        SetGeomType( UGKwkbGeometryType );

	UGKFeatureDefn *Clone();

	int         Reference() { return ++nRefCount; }
	int         Dereference() { return --nRefCount; }
	int         GetReferenceCount() { return nRefCount; }

	static UGKFeatureDefn  *CreateFeatureDefn( const char *pszName = NULL );
	static void         DestroyFeatureDefn( UGKFeatureDefn * );



};

#endif